Not So Fast, Bucko

The holiday season brings snowy, cold weather and time off. It’s this combination of factors that entices me into thinking of things I’d normally regard as dull or lacking substance. And because many of you, unlike me, lead interesting lives, I’ve thought of the problems regarding a Retina Display in the next iPad so you don’t have to.

Apple made a bit of a splash with the launch of the iPhone 4. One of the most lauded features is its “Retina Display” – Apple’s name for its 326 pixel-per-inch screen. It is the highest-resolution display currently shipping in a consumer product, and is roughly equivalent to the quality of a printed page. It is with this display that Apple made two very intelligent decisions: the first was that they placed the display in a product they knew would be a hot seller in a competitive market. This ensured that it would be a feature consumers would be exposed to on a regular basis, and would be something they’d demand in competitive products.

The second intelligent decision was to double the resolution by quadrupling the amount of pixels on the screen. That ensured that apps designed for previous versions of the iPhone would be perfectly doubled in both directions, reducing the need for interface designers to have to re-think the display. A 1px-tall line became a 2px-tall line, but appeared at the same physical size. This kept upgrading custom interface components to the new resolution relatively simple. And so, as the first anniversary of the iPad’s introduction draws near, rumours are swelling that the next iPad will gain one of these gorgeous displays. “Ridiculous,” I say. And, if I do say so myself, I think I might be correct. It just won’t.

The iPad currently has a resolution of 132 pixels-per-inch (PPI). Compared to a regular computer monitor, it looks great, but next to an iPhone 4 it’s positively coarse. Since the iPad is the same size as a magazine page, it would be amazing to make it look as good as one. Many have pointed out that a 300 PPI display of the same physical dimensions as the current iPad’s would have a resolution of 2,325 by 1,746px. That’s 4,059,450 pixels: more than a 370,000-pixel increase over the 27″ Cinema Display. They see this as the biggest problem: no display like this is known to exist. However, I see this as a minor technological hurdle compared to the massive headache this will cause for developers everywhere.

Remember how I pointed out that one of the most intelligent things Apple did with the iPhone 4 is to double the pixel dimensions in order to keep the physical dimensions the same? A 2,325 by 1,746px display would force developers to re-think their apps. Old apps wouldn’t work on the new display, as they would draw half-pixels that can’t exist. The apps would be blurry, not just pixellated, and entire layouts would have to be reconstructed from scratch. In order to work around this, the second-generation iPad would require a 2,048 by 1,536px screen. However, this would yield a resolution of 264PPI – still high, but far below Apple’s own definition of a Retina Display.

The only solution I can surmise that would allow Apple to build a 300PPI display into the iPad, call it a Retina Display and still be gracious to developers is to shrink the physical dimensions of the screen. A display that is 6.8 by 5.1 inches (8.5″ diagonally) would match all of the desired qualities. However, Apple has been clear that they think the 10″ (9.7″ if you’re being pedantic) form-factor is ideal. There is no single solution that would allow all the boxes to be ticked.